How a whole-foods, plant-based diet—free of all meat and animal products—has propelled one runner to ultramarathon greatness.

FOR NEARLY TWO DECADES, SCOTT JUREK has been a dominant force in the rarefied sport of ultrarunning. And perhaps just as impressive as his many victories, including seven consecutive wins at the Western States 100-Mile Endurance Run, is that he achieved these feats on an entirely plant-based diet. In this excerpt from his new memoir, Eat & Run: My Unlikely Journey to Ultramarathon Greatness, Jurek shares how turning vegan transformed his life, and how his diet might help your running, too.

When I was 10, my dad bought me a.22 caliber rifle with a polished walnut handle and a barrel made from burnished steel. His instructions were simple: If I wounded an animal, I killed it. If I killed it, I skinned, gutted, and ate it. By the time I was in sixth grade, I could yank a batch of walleye from a lake after lunch, clean them, roll them in bread crumbs, fry them in butter, and devour them before sunset. I knew how to hold an egg between my forefinger and pinky so I could break it with one hand. I could cook a pot roast, make a mean tuna noodle casserole, and slap together bag lunches for my little brother and sister before we headed to school.

My mother roasted pork, baked chicken, and broiled steak. I loved Campbell's Chicken Noodle Soup, and nothing made me happier than mounds of butter and piles of salt slathered and sprinkled on the mashed potatoes my mom made. When it came to vegetables, I had strong and—with the exception of canned corn—uniform feelings. I hated them.

No one would have picked me to be the kid who grew up to expound the benefits of a plant-based diet.

We lived at the end of a dead-end street at the edge of the woods, five miles from Proctor, Minnesota, which was another nine miles from Duluth, which was 150 miles from Minneapolis. The kids on the east side of Duluth flew in jets to family vacations. They were the sons and daughters of doctors and lawyers. We called them "cake-eaters." The kids on the west side—where I lived—were the tough rednecks. Some of us were, anyway. I was skinny and had high blood pressure and scoliosis. I got good grades, and my mom made me wear button-down shirts. I liked sports, but avoided teams in middle school because the thought of getting on a bus with a whole lot of other kids scared me. That was partly because when I was on the school bus, kids called me Pee-wee and pushed and shoved me. One kid spit on me. Others challenged me to fights.

I wasn't the boy anyone would have pointed to and said, "He's going to grow up to be a professional athlete."

Bullies didn't tend to join high school cross-country ski teams, and there was a lot of technique involved, so the sport seemed suited for someone who studied hard, like me. I joined my sophomore year, and by my junior year I was ranked 15th in the state. That summer, I was invited to attend the Team Birkie Ski Camp in Wisconsin, for the best high school cross-country skiers in the state. That's where I started my very slow transformation from serious carnivore into vegetarian, then vegan. (I actually prefer "plant-based" to vegan, because to a lot of people "vegan" sounds like "crazy.") The camp served vegetable lasagna, all kinds of salads, and whole-wheat bread. At the time, anything more than iceberg lettuce with a few cucumbers and creamy ranch dressing seemed bold if not amazingly sophisticated. I didn't have any choice, so I ate it. And I couldn't believe how good it tasted.